1. Field of the Invention
The present invention relates generally to solid surface countertop technology and, more particularly, to the production of a solid-surface countertop exhibiting a substantially flattened and outer built-up edge having a non-constant radius and with a non-tangential intersection with an upwardly facing mold surface.
2. Description of the Prior Art
A recent trend in solid-surface countertop technology is the production of resin cast countertops within open and negatively shaped mold enclosures. Applicants copending application Ser. No. 08/416,133, filed Apr. 4, 1995, now issued as U.S. Pat. No. 5,628,949 on May 13, 1997, discloses a mold process for producing a finished cultured marble countertop in which the mold includes a plurality of side members which are inwardly contoured in a generally bull-nosed fashion to facilitate the creation of a built-up edge. The side members are typically adhesively secured upon the mold surface and an outwardly curved bottom portion of the inwardly contoured side usually forms a flat outer face over which must be applied a wax or clay fillet in order to produce a substantially smoothed edge surface. The process for constructing a countertop according to this disclosure includes the steps of spraying or otherwise applying a high-quality solid surface coating onto the mold surfaces and particularly the sides, backfilling with a low-grade plasticized resin and then constructing a dam in proximity and parallel to the edges of the mold for a subsequent material pour and in order to create the built-up edge.
Also disclosed in the prior art are other variations of countertops exhibiting a built-up edge, among which are included U.S. Pat. No. 3,373,233, issued to Rondum which discloses a method for molding countertops in which a plastic laminated overlay is molded with wood chip and resin composites and, the end product of which displays an outer edge such as is shown in FIG. 6.
U.S. Pat. No. 5,354,592, issued to Miskell, teaches a solid surfacing edge treatment method and article which incorporates a number of differently configured edge treatment members. While not having any relevant application to the production of a resin pour molded countertop, Miskell does illustrate (FIGS. 11-14) some interesting variations of a bull-nosed countertop edge.
The shortcoming of the prior art mold assemblies, particularly when taking into account the creation of a solid surface countertop as disclosed in the 416,133 application, is the inability to consistently provide for an even and high quality edge finish to the bull nose. This is often a result of both the initially sprayed high quality surface coat pulling away or otherwise sagging when sprayed onto the inwardly contoured mold sides, the sides often being semicircular in shape, as well as the inability of the applied clay fillet to adequately replicate a tangential edge curvature from the semi-spherical bull nose contour to the horizontal mold face.